Problem: Can America simultaneously achieve energy independence and address global warming?
The challenge of controlling climate change is a goal that, to many, appears to be at odds with the equally important goal of energy security. However, the idea that the two goals are somehow mutually exclusive is not one accepted by ORNL energy researcher David Greene. "We don't want to sacrifice one for the other," he says. "We want—and we believe it possible—to achieve environmental goals and energy security goals at the same time.
"To help determine which technologies have the greatest potential for reaching these goals, Greene and a multidisciplinary group of researchers from across the laboratory conducted the ORNL Energy Assurance Study to determine (1) which energy goals are feasible, (2) the technologies needed to realize these goals, and (3) where best to deploy research and development efforts.
"The good news," says Greene, "is that, with technology advances in most areas, the goals are achievable. More good news is that, if we can master carbon capture and storage and identify environmentally acceptable ways of producing domestic fossil fuels, then the conflict between climate and energy security goals will be very, very small."
Greene contends the real challenge is to assure a high probability of success for 11 specific technologies. "This means that we must pursue all 11 as if we needed every one to succeed," he says.
The Energy Assurance Study had two fundamental premises: First, we must control climate change and solve the global problem of oil dependence. Second, achieving these two broad goals at an acceptable financial cost will depend upon advanced technologies. The uncertainty lies in advancing any area of technology to the point of making a significant contribution. "The focus on this uncertainty enables our study to provide a different perspective on the importance of research and development," Greene says.
Defining the Goals
Greene notes that while many studies have focused on the feasibility and cost of achieving climate goals, only a few have considered the energy security side of the equation—and many of these studies have posited the impractical goals of an oil-free economy or the elimination of oil imports. "Both of these positions are too extreme and not reasonable," Greene says. "We want to achieve a situation in which our economy and foreign policy are free from the undue influence of nations that supply oil, where we don't worry about the price of oil any more than we worry about the price of copper."
Greene and his colleagues have developed a model of the world oil market that enables them to project whether a particular set of strategies would result in oil independence. The model takes account of oil market uncertainty by simulating thousands of possible future scenarios. Using this model, they have determined that oil independence—defined as a situation in which it is 95% likely that the nation will spend less than 1% of its gross domestic product on oil in any given year—could be achieved by 2030 through improving America's petroleum supply/demand balance by 11 million barrels a day.
Greene stresses that energy independence does not mean absolute independence from imported oil. "The key," he says, "is shrinking U.S. potential economic vulnerability to a small and manageable problem." This is done by decreasing demand through energy efficiency and increasing supply through the use of more environmentally benign fossil fuels. "Imports will certainly go down a great deal," Greene observes, "but they need not be eliminated and are not the sole focus."
On the climate front, most studies estimate that the world will need to reduce greenhouse gas (GHG) emissions 50 to 80 percent—a significant range—by 2050 in order to stabilize atmospheric CO2 at levels that will avoid dangerous climate changes.
"In our study, we assumed that we want to do both of these things at the same time," Greene says. "Secondly, we recognized that not every technology we need will be available. Progress with every technology is not a sure thing. Even technologies we are fairly sure of are not a done deal."
Assessing the Options
To develop a comprehensive picture of current and near-future policy options, ORNL scientists and engineers were asked to provide assessments of the technologies they thought would be the most effective in meeting the climate and energy goals.
"A study like this requires experts in every phase of the energy system—people who know the electricity grid, transportation, solar energy, nuclear energy, and so on," says Greene. "The credibility of the study really rests on those folks. Only a place like ORNL with a breadth of research and a high level of expertise can undertake a project on this scale."
The group's study examined these broad technologies:
Carbon capture and storage
Transportation energy efficiency
Buildings energy efficiency
Industrial energy efficiency
Electric drive vehicles
Advanced fossil liquid fuels
Efficient electricity generation and transmission
The study's authors took a novel approach to determining which technologies would be available to address the problems. "People usually build scenarios," Greene said. "They assume we will have certain technologies and that these technologies will cost a specific amount of money. Based on this rigid scenario they determine what the future would look like." In contrast, the ORNL study approaches the problem from a different perspective: Inserting a level of uncertainty about which, if any, of these technologies will be available and in what year, the study seeks to understand the chances of solving the twin challenges of energy security and climate change. Perhaps even more intriguing, the study seeks to determine which of the 11 technologies are indispensable parts of the solution.
Using the data gathered from ORNL researchers, as well as from other studies by the International Energy Agency and the National Academy of Sciences, the technologies were analyzed in terms of their impact on U.S. oil dependence in 2030 and on global GHG emissions in 2050."
The results indicate several combinations of technologies are capable of reaching the goal of oil independence in 2030. The team took encouragement from the fact that some of these combinations could also achieve up to a 70% reduction in GHG by 2050.
The group next looked at the combinations that solved both problems, seeking to identify which technologies were critical. "For example," says Greene, "what if wind power or nuclear remain at current levels?" Greene explains that, if policymakers want 95% certainty that the challenges of oil independence and GHG emissions can be solved simultaneously, the crucial question is, "How confident do we have to be that any single technology will be successful?" "It turns out that we need to be at least 50-50 or better on every technology," he says. "The message is that we really must work hard on developing all of these technologies to be sure that most of them will be available."
"The only technology that was absolutely essential to meeting the greenhouse gas goal was carbon capture and sequestration (CCS)," Greene says. "Similarly, advanced fossil technologies, like oil shale, coal to liquids, and environmentally safe oil drilling, were shown to be absolutely essential to meeting our oil dependence goal."
Other technologies, such as transportation energy efficiency, were also important, but only the removal of CCS and advanced fossil technologies resulted in zero probability of meeting GHG and energy independence goals.
The study made clear a final point: Time is of the essence. "We cannot just sit back and wait for someone to invent something to take care of the problem," Greene says.
"The success of our efforts to address climate change and energy security has a critical dependence on advancing technology," says Greene. "This study is just a starting point for understanding and measuring the importance of energy research to the lives of our children."
The Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time.